Coffee aroma gas is commonly used to enhance the aroma of various coffee products. To accomplish this, the coffee aroma gas is incorporated into a liquid carrier such as coffee oil and then used to aromatize the various coffee products.
For example, U.S. Pat. No. 4,335,149 to Stipp (assigned to The Procter & Gamble Company) issued Jun. 15, 1982, discloses a method for the direct condensation of coffee aroma gas onto a fluidized bed of cryofied coffee oil particles. A bed of particulated solid coffee oil is placed in a vessel cooled by a cryogenic fluid. The particulated solids are fluidized to provide an adsorbent bed thereof. Gaseous aroma volatiles from a coffee aroma gas are then condensed onto the cooled and fluidized bed of particles having a temperature of below -150.degree. F. The aromatized particles thus formed can be equilibrated, melted and then added to instant coffee to provide aroma. Stipp teaches that it is usually desirable to remove any moisture from the coffee aroma gas prior to condensation to remove undesirable heat loads and to minimize plugging of the fluidized bed of cryofied coffee oil particles. Although Stipp does not disclose a method for doing so, it was well known that water-cooled condensers could be used to remove some of the aroma gas moisture, typically up to about 50% of the aroma gas moisture.
An improved method for removing moisture from coffee aroma pas was described in U.S. patent application, Ser. No. 07/902,747, filed Jun. 23, 1992, and now abandoned. In the method described therein, moisture is removed directly from coffee aroma gas by passing it through a bed of hydratable calcium sulfate granules. The resulting desiccated gas is then condensed and combined with an aroma carrier, e.g., coffee oil, equilibrated and melted. The melted product is an aromatized coffee oil that can be added to instant coffee to provide aroma. Removing moisture directly from the coffee aroma gas helps minimize the generation of excessive sulfurous aromas in the aromatized coffee oil. In the presence of water, aromatized coffee oils can rapidly develop excessive sulfurous aromas.
It has been found, however, that the desiccant-treated coffee aroma gas made according to the Patent Application disclosure often exhibits an unbalanced and excessively musty aroma. Aromatized coffee oil containing this desiccant-treated coffee aroma gas likewise often exhibits an unbalanced and excessively musty aroma.
It is therefor an object of the present invention to provide a process for removing moisture from coffee aroma gas using a calcium sulfate desiccant, which process does not cause the development of unbalanced and excessively musty aromas in the desiccant-treated coffee aroma gas.
These and other objects of this invention will become evident from the disclosure herein.